1. Field of the Invention
The present invention relates to a material classification device that removes solid material and fluid from the beds of bodies of water and then separates a portion of those entrained solid materials from the fluid. The device is particularly suitable for the extraction of gold from alluvial material. The device, being small and lightweight, is suitable for use by a single individual either above or below the water surface.
2. Description of the Prior Art
Many devices have been used over the years to separate materials that have a relatively high specific gravity from lighter materials. Sluice boxes, similar to that disclosed by the patent to George Gates, U.S. Pat. No. 482,241 are well known. Many of these devices contain various sieving and screening methods to classify the materials.
Frequently dredges are used to vacuum up material from the bottoms of rivers and lakes, which material is then processed by large sluice boxes in which the fluid and material are passed over classifier screens to separate the heavier solids from the other solid material. Some classifier devices use ribbed constructions within the sluice box to capture the smaller relatively heavy particles.
U.S. Pat. No. 1,637,625, issued to E. Shaw, discloses another type of device that is used to clean and classify sand particles. The device uses a series of chambers to collect various sized particles.
Notwithstanding the current art, it remains clear that there is a need for light weight devices that can be used by an individual to dredge material from the bottoms of streams, lakes, or other bodies of water, and then separate and capture the heavier desirable solid materials simultaneously with the dredging operation. A device that has an enclosed capture system would permit working above or below the surface of the body of water.